Influence of annealing temperature on optical properties of titanium oxide thin films

The influence of annealing temperature on optical properties of TiO₂ thin films prepared using the mid-frequency AC magnetron sputtering technique was studied to design TiO₂ thin film annealing process. The transmittance and reflectance spectra of TiO₂ thin films on fused silica substrate were measured by a spectrophotometer. The reflective indices of the films were calculated using the envelope method and the extinction coefficients were determined using the empirical formula method. The results show that the refractive index of the TiO₂ thin films increases with annealing temperature while the film extinction coefficient decreases a little at lower annealing temperatures. The TiO₂ thin film annealed at 500°C has the best optical properties.